How long does flu last and is it serious?

If you have flu, you generally start to feel ill within a few days of being infected.

You should begin to feel much better within a week or so, although you may feel tired for much longer.

You will usually be most infectious from the day your symptoms start and for a further three to seven days. Children and people with weaker immune systems may remain infectious for longer.

Most people will make a full recovery and won't experience any further problems, but elderly people and people with certain long-term medical conditions are more likely to have a bad case of flu or develop a serious complication, such as a chest infection.

How you catch flu

The flu virus is contained in the millions of tiny droplets that come out of the nose and mouth when someone who is infected coughs or sneezes.

These droplets typically spread about one metre. They hang suspended in the air for a while before landing on surfaces, where the virus can survive for up to 24 hours.

Anyone who breathes in the droplets can catch flu. You can also catch the virus by touching the surfaces that the droplets have landed on if you pick up the virus on your hands and then touch your nose or mouth.

Everyday items at home and in public places can easily become contaminated with the flu virus, including food, door handles, remote controls, handrails, telephone handsets and computer keyboards. Therefore, it's important to wash your hands frequently.

You can catch flu many times, because flu viruses change regularly and your body won't have natural resistance to the new versions.

Preventing the spread of flu

You can help stop yourself catching flu or spreading it to others with good hygiene measures.